Conduit pipes, for housing and protecting electrical wires, are generally cut to lengths at construction sites. Historically a pipe cutter with two rollers and a rotating cutter disk was used to cut pipe. These cutters are hand operated, slow, reduce the inside diameter of pipes and form sharp edges on the inside of pipes. Sharp edges have been flattened to some extent by hand reamers that ream the inside only. Hand reaming is also a slow operation and generally does not restore the inside diameter of the pipe.
Electricity is available on most construction sites today. The old hand cutters with a rotating cutter disk have been replaced by power cutters that can cut a two inch diameter pipe in seconds. These power cutters include band saws, jigsaws, chop saws, etc. Some of these saws have teeth that cut metal. Others have rotating disks with an abrasive material that cuts metal. All of them are relatively fast.
The cuts made by the motor driven cutters described above do not reduce the inside diameter of a pipe significantly. However they do leave sharp edges and burrs. These sharp edges and burrs can damage insulation and they also damage the wire covered by the insulation. Sharp edges and burrs also make it difficult to pull cables through the conduit.
Removal of sharp edges and burrs from the cut ends of conduit is complicated by the fact that the cuts made by power saws may not be perpendicular to the center axis of the pipe. When the end of a pipe is cut at an angle of less than 90.degree. relative to the axis of the pipe, the sharp edges that are produced become elliptical. Removing sharp edges of an elliptical surface generally results in too much material being removed in some areas. Pipes tend to be weakened in areas where excess material is removed.